Shin Dong-hyuk was born in 1982 in the North Korean slave labour camp known as Camp 14, but that didn't mean he had a close relationship with his mother. When he was 14 years old, he overheard her helping to plot his brother's escape and reported her to the camp authorities, in the hope of gaining favourable treatment.

For his trouble, he was tortured by being hung on a metal hook over a charcoal fire, interrogated and held in solitary confinement. When he was released from solitary, Shin was driven to an execution ground with his father. They were placed at the front of the crowd to watch the day's entertainment.

I thought, from a human rights point of view, why are the lives of two American reporters deemed more worthy than those of 200,000 North Korean inmates?

Marc Wiese, film director

Shin watched as the guards shot his brother and hung his mother. Even more tragically, he didn't feel a thing: he had been so brainwashed by the guards that he felt the murder of his brother and mother were necessary punishments to maintain order in North Korea.

"I had not yet learned that I was meant to feel sad about the death of my mother," Shin says.

Shin, who spent his first 23 years in Camp 14, is the only person born in a slave labour camp known to have escaped. The breakout, which happened in 2005, and his horrifying life inside the camp, are the subject of Camp 14 - Total Control Zone, a powerful and measured documentary about Shin's life made by German director Marc Wiese. The film - which uses animation to portray life-altering sequences from Shin's past - was screened recently in New York and other US cities, as part of the travelling Human Rights Watch Film Festival.

Wiese spent 15 days interviewing Shin, who now lives in Seoul and campaigns for human rights, about his life in the labour camp. The result is a harrowing film, but a necessary one: although their existence is well-documented, few outside the Korean peninsula are aware such camps exist.

Wiese was moved to make Camp 14 when he read a newspaper article about Shin's experiences written by American journalist Blaine Harden. (Harden also published a book entitled Escape from Camp 14: One Man's Remarkable Odyssey from North Korea to Freedom in the West.) "I realised this man lived 23 years in the camp and, because of the rule that inmates are forbidden to talk about the outside world, he never realised the world outside was any different to what went on in the camp. At that moment, I said to myself, 'I want to make this story'," Wiese says.

The filmmaker had also followed in the media the 2009 arrest, and subsequent release, of two Asian-American journalists, Euna Lee and Laura Lin. The pair had been sent to a hard labour camp in North Korea when they naively arrived in the country to report about events there. The fact that the Western media turned their attention away from the internment camps as soon as the two were released concerned Wiese. "Everyone reported on it for about three weeks, but as soon as they were set free, the reports stopped. I thought, from a human rights point of view, why are the lives of two American reporters deemed more worthy than those of 200,000 North Korean inmates?" he says.

Shin had bravely gone public with his experiences in the hope of drawing international attention to the camps. Although Wiese had no reason to disbelieve the North Korean defector, he first ascertained Shin was telling the truth.

David Hawk's 2003 publication The Hidden Gulag: Exposing North Korea's Prison Camps, which featured prisoner testimonies and satellite photographs of the camps, provided corroboration. Wiese also discovered the South Korean security services, who were at first sceptical about Shin's description of life in the camps, were satisfied he was telling the truth.

"When [Shin] arrived in the South Korean consulate in Shanghai after his escape, nobody believed him to start with. They took him to Seoul, and the authorities said he was not telling the truth. There was no one to back him up, as he was the only person to have escaped from the labour camps," Wiese says.

"They interrogated him for weeks [but he] knew so much about the camp, and described everything in such detail, they decided he was telling the truth."

The details about Camp 14, which was established around 1959 in Kaechon county about 80 kilometres north of Pyongyang, and still operational, are horrifying. The camp is for political prisoners and their families, not criminals.

Shin describes some of the many rules: anyone who tries to escape will be shot immediately; anyone who fails to obey an order will be shot immediately; anyone who fails to carry out the work allocated to them will be shot immediately; and anyone who disobeys the camp rules will be shot immediately. These rules apply to children as well as adults.

The inmates are beaten on a daily basis: Shin estimates he was beaten around 7,000 times during his internment, sometimes nearly to death. He also describes how a young girl was beaten for five hours by a teacher in front of the class in the camp school, because the teacher found a grain of food in her pocket. She died.

Wiese says he wanted the film to be more than a litany of the camp guards' crimes, and realised it would be more effective if he could interview some of the perpetrators. With the aid of Korean journalist Stella Kim, he tracked down Hyon Kwon, who commanded the prison guards in Camp 22, and secret service police member Oh Yang-nam, both now in South Korea. They agreed to be interviewed on camera.

Wiese says this added a new level to the documentary. "This changed the film from being a victim's film to one about how a system is able to format people - both the victims and the perpetrators," he says.

"I wanted to make the viewer consider how we ourselves would have reacted if we had been part of the camp system," Wiese says. The North Korean regime is a master of brainwashing, he concludes: it turns ordinary men into monsters and convinces prisoners that the cruelty inflicted on them is necessary for preservation of the state.

"Most of the people in North Korea are probably formatted [to believe in the system]," Wiese says. "There are doubtlessly some people who are able to resist, who have not been formatted, and who are free in their minds. But many North Koreans have been born into the system. They don't know it's a terror system. I don't think the majority would want to change it."